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Arora I, Mal P, Arora P, Paul A, Kumar M. GABAergic implications in anxiety and related disorders. Biochem Biophys Res Commun 2024; 724:150218. [PMID: 38865810 DOI: 10.1016/j.bbrc.2024.150218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/05/2024] [Accepted: 06/02/2024] [Indexed: 06/14/2024]
Abstract
Evidence indicates that anxiety disorders arise from an imbalance in the functioning of brain circuits that govern the modulation of emotional responses to possibly threatening stimuli. The circuits under consideration in this context include the amygdala's bottom-up activity, which signifies the existence of stimuli that may be seen as dangerous. Moreover, these circuits encompass top-down regulatory processes that originate in the prefrontal cortex, facilitating the communication of the emotional significance associated with the inputs. Diverse databases (e.g., Pubmed, ScienceDirect, Web of Science, Google Scholar) were searched for literature using a combination of different terms e.g., "anxiety", "stress", "neuroanatomy", and "neural circuits", etc. A decrease in GABAergic activity is present in both anxiety disorders and severe depression. Research on cerebral functional imaging in depressive individuals has shown reduced levels of GABA within the cortical regions. Additionally, animal studies demonstrated that a reduction in the expression of GABAA/B receptors results in a behavioral pattern resembling anxiety. The amygdala consists of inhibitory networks composed of GABAergic interneurons, responsible for modulating anxiety responses in both normal and pathological conditions. The GABAA receptor has allosteric sites (e.g., α/γ, γ/β, and α/β) which enable regulation of neuronal inhibition in the amygdala. These sites serve as molecular targets for anxiolytic medications such as benzodiazepine and barbiturates. Alterations in the levels of naturally occurring regulators of these allosteric sites, along with alterations to the composition of the GABAA receptor subunits, could potentially act as mechanisms via which the extent of neuronal inhibition is diminished in pathological anxiety disorders.
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Affiliation(s)
- Indu Arora
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Pankaj Mal
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Poonam Arora
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Anushka Paul
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Manish Kumar
- Chitkara College of Pharmacy, Chitkara University, Punjab, India.
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2
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Chang Y, Xie X, Liu Y, Liu M, Zhang H. Exploring clinical applications and long-term effectiveness of benzodiazepines: An integrated perspective on mechanisms, imaging, and personalized medicine. Biomed Pharmacother 2024; 173:116329. [PMID: 38401518 DOI: 10.1016/j.biopha.2024.116329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/13/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024] Open
Abstract
Benzodiazepines have been long-established treatments for various conditions, including anxiety disorders and insomnia. Recent FDA warnings emphasize the risks of misuse and dependence associated with benzodiazepines. This article highlights their benefits and potential drawbacks from various perspectives. It achieves this by explaining how benzodiazepines work in terms of neuroendocrinology, immunomodulation, sleep, anxiety, cognition, and addiction, ultimately improving their clinical effectiveness. Benzodiazepines play a regulatory role in the HPA axis and impact various systems, including neuropeptide Y and cholecystokinin. Benzodiazepines can facilitate sleep-dependent memory consolidation by promoting spindle wave activity, but they can also lead to memory deficits in older individuals due to reduced slow-wave sleep. The cognitive effects of chronic benzodiazepines use remain uncertain; however, no adverse findings have been reported in clinical imaging studies. This article aims to comprehensively review the evidence on benzodiazepines therapy, emphasizing the need for more clinical studies, especially regarding long-term benzodiazepines use.
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Affiliation(s)
- Yiheng Chang
- Department of Neurology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Xueting Xie
- Department of Neurology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Yudan Liu
- Department of Neurology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Meichen Liu
- Department of Neurology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
| | - Huimin Zhang
- Department of Neurology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
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Braga MFM, Juranek J, Eiden LE, Li Z, Figueiredo TH, de Araujo Furtado M, Marini AM. GABAergic circuits of the basolateral amygdala and generation of anxiety after traumatic brain injury. Amino Acids 2022; 54:1229-1249. [PMID: 35798984 DOI: 10.1007/s00726-022-03184-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 06/20/2022] [Indexed: 11/25/2022]
Abstract
Traumatic brain injury (TBI) has reached epidemic proportions around the world and is a major public health concern in the United States. Approximately 2.8 million individuals sustain a traumatic brain injury and are treated in an Emergency Department yearly in the U.S., and about 50,000 of them die. Persistent symptoms develop in 10-15% of the cases including neuropsychiatric disorders. Anxiety is the second most common neuropsychiatric disorder that develops in those with persistent neuropsychiatric symptoms after TBI. Abnormalities or atrophy in the temporal lobe has been shown in the overwhelming number of TBI cases. The basolateral amygdala (BLA), a temporal lobe structure that consolidates, stores and generates fear and anxiety-based behavioral outputs, is a critical brain region in the anxiety circuitry. In this review, we sought to capture studies that characterized the relationship between human post-traumatic anxiety and structural/functional alterations in the amygdala. We compared the human findings with results obtained with a reproducible mild TBI animal model that demonstrated a direct relationship between the alterations in the BLA and an anxiety-like phenotype. From this analysis, both preliminary insights, and gaps in knowledge, have emerged which may open new directions for the development of rational and more efficacious treatments.
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Affiliation(s)
- Maria F M Braga
- Department of Anatomy, Physiology and Genetics and Program in Neuroscience, Uniformed Services University of the Health Science School of Medicine, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Jenifer Juranek
- Department of Pediatric Surgery, McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth), Houston, TX, 77030, USA
| | - Lee E Eiden
- Section On Molecular Neuroscience, National Institute of Mental Health, Intramural Research Program, Bethesda, MD, 20814, USA
| | - Zheng Li
- Section On Synapse Development and Plasticity, National Institute of Mental Health, Intramural Research Program, Bethesda, MD, 20814, USA
| | - Taiza H Figueiredo
- Department of Anatomy, Physiology and Genetics and Program in Neuroscience, Uniformed Services University of the Health Science School of Medicine, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Marcio de Araujo Furtado
- Department of Anatomy, Physiology and Genetics and Program in Neuroscience, Uniformed Services University of the Health Science School of Medicine, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
| | - Ann M Marini
- Department of Neurology and Program in Neuroscience, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
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Female-specific role of ciliary neurotrophic factor in the medial amygdala in promoting stress responses. Neurobiol Stress 2022; 17:100435. [PMID: 35146079 PMCID: PMC8819478 DOI: 10.1016/j.ynstr.2022.100435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/21/2022] [Accepted: 01/24/2022] [Indexed: 11/18/2022] Open
Abstract
Ciliary neurotrophic factor (CNTF) is produced by astrocytes which have been implicated in regulating stress responses. We found that CNTF in the medial amygdala (MeA) promotes despair or passive coping, i.e., immobility in an acute forced swim stress, in female mice, while having no effect in males. Neutralizing CNTF antibody injected into the MeA of wildtype females reduced activation of downstream STAT3 (Y705) 24 and 48 h later. In concert, the antibody reduced immobility in the swim test in females and only after MeA injection, but not when injected in the central or basolateral amygdala. Antibody injected into the male MeA did not affect immobility. These data reveal a unique role of CNTF in female MeA in promoting despair or passive coping behavior. Moreover, 4 weeks of chronic unpredictable stress (CUS) increased immobility in the swim test and reduced sucrose preference in wildtype CNTF+/+, but not CNTF−/− littermate, females. Following CUS, 10 min of restraint stress increased plasma corticosterone levels only in CNTF+/+ females. In males, the CUS effects were present in both genotypes. Further, CUS increased CNTF expression in the MeA of female, but not male, mice. CUS did not alter CNTF in the female hippocampus, hypothalamus and bed nucleus of stria terminalis. This suggests that MeA CNTF has a female-specific role in promoting CUS-induced despair or passive coping, behavioral anhedonia and neuroendocrine responses. Compared to CNTF+/+ mice, CNTF−/− mice did not show differences in CUS-induced anxiety-like behavior and sensorimotor gating function as measured by elevated T-Maze, open field and pre-pulse inhibition of the acoustic startle response. Together, this study reveals a novel CNTF-mediated female-specific mechanism in stress responses and points to opportunities for developing treatments for stress-related disorders in women. CNTF in the MeA promotes despair or passive coping behavior in female mice only. Chronic stress upregulates CNTF in female but not male MeA. CNTF contributes to chronic stress-induced despair or passive coping, anhedonia and neuroendocrine responses in females only. CNTF does not affect anxiety-like behavior and sensorimotor gating function. These data reveal a novel CNTF-mediated female-specific mechanism in stress responses.
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Jafarian M, Modarres Mousavi SM, Alipour F, Aligholi H, Noorbakhsh F, Ghadipasha M, Gharehdaghi J, Kellinghaus C, Kovac S, Khaleghi Ghadiri M, Meuth SG, Speckmann EJ, Stummer W, Gorji A. Cell injury and receptor expression in the epileptic human amygdala. Neurobiol Dis 2019; 124:416-427. [DOI: 10.1016/j.nbd.2018.12.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/04/2018] [Accepted: 12/22/2018] [Indexed: 02/06/2023] Open
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An Emerging Circuit Pharmacology of GABA A Receptors. Trends Pharmacol Sci 2018; 39:710-732. [PMID: 29903580 DOI: 10.1016/j.tips.2018.04.003] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/23/2018] [Accepted: 04/17/2018] [Indexed: 12/21/2022]
Abstract
In the past 20 years we have learned a great deal about GABAA receptor (GABAAR) subtypes, and which behaviors are regulated or which drug effects are mediated by each subtype. However, the question of where GABAARs involved in specific drug effects and behaviors are located in the brain remains largely unanswered. We review here recent studies taking a circuit pharmacology approach to investigate the functions of GABAAR subtypes in specific brain circuits controlling fear, anxiety, learning, memory, reward, addiction, and stress-related behaviors. The findings of these studies highlight the complexity of brain inhibitory systems and the importance of taking a subtype-, circuit-, and neuronal population-specific approach to develop future therapeutic strategies using cell type-specific drug delivery.
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Babaev O, Piletti Chatain C, Krueger-Burg D. Inhibition in the amygdala anxiety circuitry. Exp Mol Med 2018; 50:1-16. [PMID: 29628509 PMCID: PMC5938054 DOI: 10.1038/s12276-018-0063-8] [Citation(s) in RCA: 175] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 01/25/2018] [Indexed: 01/09/2023] Open
Abstract
Inhibitory neurotransmission plays a key role in anxiety disorders, as evidenced by the anxiolytic effect of the benzodiazepine class of γ-aminobutyric acid (GABA) receptor agonists and the recent discovery of anxiety-associated variants in the molecular components of inhibitory synapses. Accordingly, substantial interest has focused on understanding how inhibitory neurons and synapses contribute to the circuitry underlying adaptive and pathological anxiety behaviors. A key element of the anxiety circuitry is the amygdala, which integrates information from cortical and thalamic sensory inputs to generate fear and anxiety-related behavioral outputs. Information processing within the amygdala is heavily dependent on inhibitory control, although the specific mechanisms by which amygdala GABAergic neurons and synapses regulate anxiety-related behaviors are only beginning to be uncovered. Here, we summarize the current state of knowledge and highlight open questions regarding the role of inhibition in the amygdala anxiety circuitry. We discuss the inhibitory neuron subtypes that contribute to the processing of anxiety information in the basolateral and central amygdala, as well as the molecular determinants, such as GABA receptors and synapse organizer proteins, that shape inhibitory synaptic transmission within the anxiety circuitry. Finally, we conclude with an overview of current and future approaches for converting this knowledge into successful treatment strategies for anxiety disorders.
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Affiliation(s)
- Olga Babaev
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Carolina Piletti Chatain
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany.
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9
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Liu M, Fitzgibbon M, Wang Y, Reilly J, Qian X, O'Brien T, Clapcote S, Shen S, Roche M. Ulk4 regulates GABAergic signaling and anxiety-related behavior. Transl Psychiatry 2018; 8:43. [PMID: 29391390 PMCID: PMC5804027 DOI: 10.1038/s41398-017-0091-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 10/09/2017] [Accepted: 11/30/2017] [Indexed: 01/15/2023] Open
Abstract
Excitation/inhibition imbalance has been proposed as a fundamental mechanism in the pathogenesis of neuropsychiatric and neurodevelopmental disorders, in which copy number variations of the Unc-51 like kinase 4 (ULK4) gene encoding a putative Serine/Threonine kinase have been reported in approximately 1/1000 of patients suffering pleiotropic clinical conditions of schizophrenia, depression, autistic spectrum disorder (ASD), developmental delay, language delay, intellectual disability, or behavioral disorder. The current study characterized behavior of heterozygous Ulk4 +/tm1a mice, demonstrating that Ulk4 +/tm1a mice displayed no schizophrenia-like behavior in acoustic startle reactivity and prepulse inhibition tests or depressive-like behavior in the Porsolt swim or tail suspension tests. However, Ulk4 +/tm1a mice exhibited an anxiety-like behavioral phenotype in several tests. Previously identified hypo-anxious (Atp1a2, Ptn, and Mdk) and hyper-anxious (Gria1, Syngap1, and Npy2r) genes were found to be dysregulated accordingly in Ulk4 mutants. Ulk4 was found to be expressed in GABAergic neurons and the Gad67+ interneurons were significantly reduced in the hippocampus and basolateral amygdala of Ulk4 +/tm1a mice. Transcriptome analyses revealed a marked reduction of GABAergic neuronal subtypes, including Pvalb, Sst, Cck, Npy, and Nos3, as well as significant upregulation of GABA receptors, including Gabra1, Gabra3, Gabra4, Gabra5, and Gabrb3. This is the first evidence that Ulk4 plays a major role in regulating GABAergic signaling and anxiety-like behavior, which may have implications for the development of novel anxiolytic treatments.
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Affiliation(s)
- Min Liu
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Marie Fitzgibbon
- Physiology, School of Medicine, Galway Neuroscience Centre and Centre for Pain Research, National University of Ireland Galway, Galway, Ireland
| | - Yanqin Wang
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland
- Department of Physiology, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Jamie Reilly
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Xiaohong Qian
- National Center for Protein Sciences, Beijing Proteome Research Center, National Engineering Research Center for Protein Drugs, Beijing Institute of Radiation Medicine, Beijing, China
| | - Timothy O'Brien
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Steve Clapcote
- School of Biomedical Sciences, University of Leeds, Leeds, UK
| | - Sanbing Shen
- Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland.
| | - Michelle Roche
- Physiology, School of Medicine, Galway Neuroscience Centre and Centre for Pain Research, National University of Ireland Galway, Galway, Ireland.
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Should Benzodiazepines and Anticonvulsants Be Used During Electroconvulsive Therapy?: A Case Study and Literature Review. J ECT 2017; 33:237-242. [PMID: 28767528 DOI: 10.1097/yct.0000000000000441] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE This study aims to investigate the clinical effects of benzodiazepines or anticonvulsant use during a course of electroconvulsive therapy (ECT). METHOD A case report study of a patient who received ECT with and without concomitant flurazepam and pregabalin is presented. The literature on the use of benzodiazepines and anticonvulsants during ECT is reviewed. RESULTS A woman with treatment resistant depression received a course of ECT while taking flurazepam and pregabalin, but seizures were of short duration and symptomatic improvement was minimal. After discontinuation of flurazepam and pregabalin, a course of right unilateral ultrabrief ECT was associated with adequate seizures and remission of depression and suicidal ideation. Our literature review suggests that benzodiazepines decrease seizure duration, but most evidence shows no association with increased seizure threshold. One prospective RCT and 3 large retrospective studies found that benzodiazepines compromise the efficacy of unilateral but not bilateral ECT. Regarding anticonvulsants, several studies had varied and contradictory results on their effect on seizure duration and seizure threshold. Of the 2 large retrospective studies and 3 RCTs, only 1 retrospective study showed that anticonvulsants decrease the efficacy of ECT. CONCLUSIONS Judicious assessment of all medications used in combination with ECT is recommended. Overall, published studies suggest that benzodiazepines and anticonvulsants impact the clinical outcomes of ECT less than what would be expected given their pharmacologic effects. However, there are significant gaps in the literature, including a lack of study on suprathreshold stimulation of right unilateral ECT and the possibility of a greater effect with higher medication doses.
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Stefanits H, Milenkovic I, Mahr N, Pataraia E, Hainfellner JA, Kovacs GG, Sieghart W, Yilmazer-Hanke D, Czech T. GABAAreceptor subunits in the human amygdala and hippocampus: Immunohistochemical distribution of 7 subunits. J Comp Neurol 2017; 526:324-348. [DOI: 10.1002/cne.24337] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 09/12/2017] [Accepted: 09/19/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Harald Stefanits
- Department of Neurosurgery; Medical University of Vienna; Vienna Austria
- Institute of Neurology, Medical University of Vienna; Vienna Austria
| | - Ivan Milenkovic
- Department of Clinical Neurology; Medical University of Vienna; Vienna Austria
| | - Nina Mahr
- Department of Neurosurgery; Medical University of Vienna; Vienna Austria
| | - Ekaterina Pataraia
- Department of Clinical Neurology; Medical University of Vienna; Vienna Austria
| | | | - Gabor G. Kovacs
- Institute of Neurology, Medical University of Vienna; Vienna Austria
| | - Werner Sieghart
- Center for Brain Research, Department of Molecular Neurosciences; Medical University of Vienna; Vienna Austria
| | - Deniz Yilmazer-Hanke
- Clinical Neuroanatomy, Neurology Department, Medical Faculty; Ulm University; Ulm Germany
| | - Thomas Czech
- Department of Neurosurgery; Medical University of Vienna; Vienna Austria
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The anxiolytic-like effect of rutin in rats involves GABAA receptors in the basolateral amygdala. Behav Pharmacol 2017; 28:303-312. [DOI: 10.1097/fbp.0000000000000290] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Zhong M, Shoemake C, Fuller A, White D, Hanks C, Brocksmith D, Liu J, Gad S, Bouchard G, Stricker-Krongrad A. Development of a Functional Observational Battery in the Minipig for Regulatory Neurotoxicity Assessments. Int J Toxicol 2017; 36:113-123. [DOI: 10.1177/1091581816686049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A functional observational battery (FOB) is recommended as the first-tier neurotoxicity screening in the preclinical safety pharmacology testing guidelines. Minipigs have increasingly been used in regulatory toxicology studies; however, no current FOB protocol is available for neurotoxicity testing in these species. Hence, a minipig FOB instrument was developed. A complete crossover study with Sinclair minipigs was performed to evaluate physiologic, neurologic, and behavioral effects of amphetamine, ketamine, and diazepam. The treated minipigs were first observed in their home cage, were video-recorded for 10 minutes in an open field, and then went through a complete neurologic examination. Both ketamine and diazepam were shown to reduce the freezing and behavior shifts of treated minipigs, while increasing their exploratory behaviors. Both drugs also caused muscular and gait impairment. The effects of ketamine and diazepam were consistent with their roles as central nervous system (CNS) suppressants. Unique effects were also observed with ketamine and diazepam treatments, which may reflect their unique mechanisms of action. Consistent with its role as a CNS stimulant, amphetamine caused the treated minipigs to be hyperactive and to display increased freezing and behavior shifts and reduced exploring activities. These effects of amphetamine were opposite to those observed with ketamine and diazepam. Amphetamine also increased locomotion in the treated minipigs. The present effects of amphetamine, ketamine, and diazepam are in agreement with observations by others. In conclusion, the minipig is a suitable species for FOB evaluation of pharmaceuticals in preclinical safety pharmacology testing.
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Affiliation(s)
- Miao Zhong
- Sinclair Research Center, LLC, Auxvasse, MO, USA
| | | | - Amber Fuller
- Sinclair Research Center, LLC, Auxvasse, MO, USA
| | - David White
- Sinclair Research Center, LLC, Auxvasse, MO, USA
| | - Chris Hanks
- Sinclair Research Center, LLC, Auxvasse, MO, USA
| | | | - Jason Liu
- Sinclair Research Center, LLC, Auxvasse, MO, USA
| | - Shayne Gad
- Gad Consulting Services, Raleigh, NC, USA
| | - Guy Bouchard
- Sinclair Research Center, LLC, Auxvasse, MO, USA
- Sinclair BioResources, LLC, Auxvasse, MO, USA
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Involvement of ATP-sensitive potassium channels and the opioid system in the anticonvulsive effect of zolpidem in mice. Epilepsy Behav 2016; 62:291-6. [PMID: 27521722 DOI: 10.1016/j.yebeh.2016.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 01/30/2023]
Abstract
Zolpidem is a hypnotic medication that mainly exerts its function through activating γ-aminobutyric acid (GABA)A receptors. There is some evidence that zolpidem may have anticonvulsive effects. However, the mechanisms underlying this effect have not been elucidated yet. In the present study, we used the pentylentetrazole (PTZ)-induced generalized seizure model in mice to investigate whether zolpidem can affect seizure threshold. We also further evaluated the roles of ATP-sensitive potassium (KATP) channels as well as μ-opioid receptors in the effects of zolpidem on seizure threshold. Our data showed that zolpidem in a dose-dependent manner increased the PTZ-induced seizure threshold. The noneffective (i.e., did not significantly alter the PTZ-induced seizure threshold by itself) doses of KATP channel blocker (glibenclamide) and nonselective opioid receptor antagonist (naloxone) were able to inhibit the anticonvulsive effect of zolpidem. Additionally, noneffective doses of either KATP channel opener (cromakalim) or nonselective μ-opioid receptor agonist (morphine) in combination with a noneffective dose of zolpidem exerted a significant anticonvulsive effect on PTZ-induced seizures in mice. A combination of noneffective doses of naloxone and glibenclamide, which separately did not affect zolpidem effect on seizure threshold, inhibited the anticonvulsive effects of zolpidem. These results suggest a role for KATP channels and the opioid system, alone or in combination, in the anticonvulsive effects of zolpidem.
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Goddard AW. Cortical and subcortical gamma amino acid butyric acid deficits in anxiety and stress disorders: Clinical implications. World J Psychiatry 2016; 6:43-53. [PMID: 27014597 PMCID: PMC4804267 DOI: 10.5498/wjp.v6.i1.43] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/18/2015] [Accepted: 01/29/2016] [Indexed: 02/05/2023] Open
Abstract
Anxiety and stress disorders are a major public health issue. However, their pathophysiology is still unclear. The gamma amino acid butyric acid (GABA) neurochemical system has been strongly implicated in their pathogenesis and treatment by numerous preclinical and clinical studies, the most recent of which have been highlighted and critical review in this paper. Changes in cortical GABA appear related to normal personality styles and responses to stress. While there is accumulating animal and human neuroimaging evidence of cortical and subcortical GABA deficits across a number of anxiety conditions, a clear pattern of findings in specific brain regions for a given disorder is yet to emerge. Neuropsychiatric conditions with anxiety as a clinical feature may have GABA deficits as an underlying feature. Different classes of anxiolytic therapies support GABA function, and this may be an area in which newer GABA neuroimaging techniques could soon offer more personalized therapy. Novel GABAergic pharmacotherapies in development offer potential improvements over current therapies in reducing sedative and physiologic dependency effects, while offering rapid anxiolysis.
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Acute Treatment with a Novel TRPC4/C5 Channel Inhibitor Produces Antidepressant and Anxiolytic-Like Effects in Mice. PLoS One 2015; 10:e0136255. [PMID: 26317356 PMCID: PMC4552833 DOI: 10.1371/journal.pone.0136255] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/03/2015] [Indexed: 12/28/2022] Open
Abstract
Transient receptor potential canonical (TRPC) channels are widely expressed in brain and involved in various aspects of brain function. Both TRPC4 and TRPC5 have been implicated in innate fear function, which represents a key response to environmental stress. However, to what extent the TRPC4/C5 channels are involved in psychiatric disorders remains unexplored. Here, we tested the antidepressant and anxiolytic-like effects of a newly identified TRPC4/C5 inhibitor, M084. We show that a single intraperitoneal administration of M084 at 10 mg/kg body weight to C57BL/6 male mice significantly shortened the immobility time in forced swim test and tail suspension test within as short as 2 hours. The M084-treated mice spent more time exploring in illuminated and open areas in light/dark transition test and elevated plus maze test. In mice subjected to chronic unpredictable stress, M084 treatment reversed the enhanced immobility time in forced swim test and decreased the latency to feed in novelty suppressed feeding test. The treatment of M084 increased BDNF expression in both mRNA and protein levels, as well as phosphorylation levels of AKT and ERK, in prefrontal cortex. Our results indicate that M084 exerts rapid antidepressant and anxiolytic-like effects at least in part by acting on BDNF and its downstream signaling. We propose M084 as a lead compound for further druggability research.
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Butkovich LM, DePoy LM, Allen AG, Shapiro LP, Swanson AM, Gourley SL. Adolescent-onset GABAA α1 silencing regulates reward-related decision making. Eur J Neurosci 2015; 42:2114-2121. [PMID: 26096050 DOI: 10.1111/ejn.12995] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 06/11/2015] [Accepted: 06/17/2015] [Indexed: 11/30/2022]
Abstract
The GABAA receptor mediates fast, inhibitory signaling, and cortical expression of the α1 subunit increases during postnatal development. Certain pathological stimuli such as stressors or prenatal cocaine exposure can interfere with this process, but causal relationships between GABAA α1 deficiency and complex behavioral outcomes remain unconfirmed. We chronically reduced GABAA α1 expression selectively in the medial prefrontal cortex (prelimbic subregion) of mice using viral-mediated gene silencing of Gabra1. Adolescent-onset Gabra1 knockdown delayed the acquisition of a cocaine-reinforced instrumental response but spared cocaine seeking in extinction and in a cue-induced reinstatement procedure. To determine whether response acquisition deficits could be associated with impairments in action-outcome associative learning and memory, we next assessed behavioral sensitivity to instrumental contingency degradation. In this case, the predictive relationship between familiar actions and their outcomes is violated. Adolescent-onset knockdown, although not adult-onset knockdown, delayed the expression of goal-directed response strategies in this task, resulting instead in inflexible habit-like modes of response. Thus, the maturation of medial prefrontal cortex GABAA α1 systems during adolescence appears necessary for goal-directed reward-related decision making in adulthood. These findings are discussed in the light of evidence that prolonged Gabra1 deficiency may impair synaptic plasticity.
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Affiliation(s)
| | - Lauren M DePoy
- Graduate Program in Neuroscience, Emory University.,Department of Pediatrics, Emory University.,Yerkes National Primate Research Center, Emory University
| | - Amanda G Allen
- Department of Pediatrics, Emory University.,Yerkes National Primate Research Center, Emory University
| | - Lauren P Shapiro
- Department of Pediatrics, Emory University.,Yerkes National Primate Research Center, Emory University.,Molecular and Systems Pharmacology, Emory University
| | - Andrew M Swanson
- Graduate Program in Neuroscience, Emory University.,Department of Pediatrics, Emory University.,Yerkes National Primate Research Center, Emory University
| | - Shannon L Gourley
- Graduate Program in Neuroscience, Emory University.,Department of Pediatrics, Emory University.,Yerkes National Primate Research Center, Emory University.,Department of Psychiatry and Behavioral Sciences, Emory University
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GABAAα1-mediated plasticity in the orbitofrontal cortex regulates context-dependent action selection. Neuropsychopharmacology 2015; 40:1027-36. [PMID: 25348603 PMCID: PMC4330518 DOI: 10.1038/npp.2014.292] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 10/21/2014] [Accepted: 10/22/2014] [Indexed: 01/04/2023]
Abstract
An essential aspect of goal-directed action selection is differentiating between behaviors that are more, or less, likely to be reinforced. Habits, by contrast, are stimulus-elicited behaviors insensitive to action-outcome contingencies and are considered an etiological factor in several neuropsychiatric disorders. Thus, isolating the neuroanatomy and neurobiology of goal-directed action selection on the one hand, and habit formation on the other, is critical. Using in vivo viral-mediated gene silencing, we knocked down Gabra1 in the orbitofrontal prefrontal cortex (oPFC) in mice, decreasing oPFC GABAAα1 expression, as well as expression of the synaptic marker PSD-95. Mice expressing Green Fluorescent Protein or Gabra1 knockdown in the adjacent M2 motor cortex served as comparison groups. Using instrumental response training followed by action-outcome contingency degradation, we then found that oPFC GABAAα1 deficiency impaired animals' ability to differentiate between actions that were more or less likely to be reinforced, though sensitivity to outcome devaluation and extinction were intact. Meanwhile, M2 GABAAα1 deficiency enhanced sensitivity to action-outcome relationships. Behavioral abnormalities following oPFC GABAAα1 knockdown were rescued by testing mice in a distinct context relative to that in which they had been initially trained. Together, our findings corroborate evidence that chronic GABAAα1 deficiency remodels cortical synapses and suggest that neuroplasticity within the healthy oPFC gates the influence of reward-related contextual stimuli. These stimuli might otherwise promote maladaptive habit-based behavioral response strategies that contribute to-or exacerbate-neuropsychiatric illness.
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Tang HM, Tu X, Chai YN, Zhang QY, Huang YS, Zhang Q. Contents of amino acid neurotransmitters and expression of γ-aminobutyric acid receptor in two subtypes of irritable bowel syndrome. Shijie Huaren Xiaohua Zazhi 2014; 22:4559-4565. [DOI: 10.11569/wcjd.v22.i30.4559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the feasibility of using in vivo cerebral microdialysis and high performance liquid chromatography (HPLC) to determine the contents of glutamate (Glu), glycine (Gly), γ-aminobutyric acid (γ-GABA) and taurine (Tau), and to observe the protein expression of γ-aminobutyric acid receptor A (GABAAα1) in irritable bowel syndrome with diarrhea (IBS-D) and irritable bowel syndrome with constipation (IBS-C) to investigate the preliminary pathogenesis of these two subtypes.
METHODS: Using in vitro relative recovery and in vivo relative loss ratio as monitoring indicators, the feasibility of using cerebral microdialysis and HPLC to determine the contents of Glu, Gly, Tau and γ-GABA was first explored. IBS-C was induced by cold water administration and IBS-D by folium sennae combined with restraint. Cerebral microdialysis and HPLC were then used to determine the contents of Glu, Gly, Tau and γ-GABA in the rat brain. Western blot was used to detect the expression of GABAAα1 protein in brain tissue.
RESULTS: In vivo cerebral microdialysis and HPLC were feasible for determining the contents of Glu and γ-GABA; the in vitro relative recovery rates were 21.6% and 24.5%, respectively; in vivo relative loss rates were 41.8% and 32.5%. Compared with rats in the normal group, the ratio of Glu/γ-GABA in the IBS-C and IBS-D groups significantly increased (P < 0.05). GABAAα1 protein expression in both IBS-C and IBS-D groups were significantly higher than that in the normal group (P < 0.05). In addition, GABAAα1 protein expression in the IBS-D group was significantly higher than that in the IBS-C group (P < 0.05).
CONCLUSION: The pathogenesis of IBS-C and IBS-D may be related with Glu/GABA ratio and GABAAα1 in the brain.
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20
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Implication of mGlu5 receptor in the enhancement of morphine-induced hyperlocomotion under chronic treatment with zolpidem. Eur J Pharmacol 2014; 738:360-7. [DOI: 10.1016/j.ejphar.2014.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 05/30/2014] [Accepted: 06/02/2014] [Indexed: 02/04/2023]
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21
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Lindemeyer AK, Liang J, Marty VN, Meyer EM, Suryanarayanan A, Olsen RW, Spigelman I. Ethanol-induced plasticity of GABAA receptors in the basolateral amygdala. Neurochem Res 2014; 39:1162-70. [PMID: 24710789 PMCID: PMC4121120 DOI: 10.1007/s11064-014-1297-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/24/2014] [Accepted: 03/26/2014] [Indexed: 12/25/2022]
Abstract
Acute and chronic ethanol (EtOH) administration is known to affect function, surface expression, and subunit composition of γ-aminobutyric acid (A) receptors (GABAARs) in different parts of the brain, which is believed to play a major role in alcohol dependence and withdrawal symptoms. The basolateral amygdala (BLA) participates in anxiety-like behaviors including those induced by alcohol withdrawal. In the present study we assessed the changes in cell surface levels of select GABAAR subunits in the BLA of a rat model of alcohol dependence induced by chronic intermittent EtOH (CIE) treatment and long-term (>40 days) withdrawal and investigated the time-course of such changes after a single dose of EtOH (5 g/kg, gavage). We found an early decrease in surface expression of α4 and δ subunits at 1 h following single dose EtOH treatment. At 48 h post-EtOH and after CIE treatment there was an increase in α4 and γ2, while α1, α2, and δ surface expression were decreased. To relate functional changes in GABAARs to changes in their subunit composition we analyzed miniature inhibitory postsynaptic currents (mIPSCs) and the picrotoxin-sensitive tonic current (Itonic) 48 h after EtOH intoxication. The Itonic magnitude and most of the mIPSC kinetic parameters (except faster mIPSC decay) were unchanged at 48 h post-EtOH. At the same time, Itonic potentiation by acute EtOH was greatly reduced, whereas mIPSCs became significantly more sensitive to potentiation by acute EtOH. These results suggest that EtOH intoxication-induced GABAAR plasticity in the BLA might contribute to the diminished sedative/hypnotic and maintained anxiolytic effectiveness of EtOH.
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Affiliation(s)
- A. Kerstin Lindemeyer
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Jing Liang
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Division of Oral Biology and Medicine, School of Dentistry, University of California, 10833 Le Conte Avenue, 63-078 CHS, Los Angeles, CA 90095-1668, USA
| | - Vincent N. Marty
- Division of Oral Biology and Medicine, School of Dentistry, University of California, 10833 Le Conte Avenue, 63-078 CHS, Los Angeles, CA 90095-1668, USA
| | - Edward M. Meyer
- Division of Oral Biology and Medicine, School of Dentistry, University of California, 10833 Le Conte Avenue, 63-078 CHS, Los Angeles, CA 90095-1668, USA
| | - Asha Suryanarayanan
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Division of Oral Biology and Medicine, School of Dentistry, University of California, 10833 Le Conte Avenue, 63-078 CHS, Los Angeles, CA 90095-1668, USA
| | - Richard W. Olsen
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Igor Spigelman
- Division of Oral Biology and Medicine, School of Dentistry, University of California, 10833 Le Conte Avenue, 63-078 CHS, Los Angeles, CA 90095-1668, USA
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Heldt SA, Zimmermann K, Parker K, Gaval M, Ressler KJ. BDNF deletion or TrkB impairment in amygdala inhibits both appetitive and aversive learning. J Neurosci 2014; 34:2444-50. [PMID: 24523535 PMCID: PMC3921419 DOI: 10.1523/jneurosci.4085-12.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 12/29/2013] [Accepted: 12/30/2013] [Indexed: 11/21/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is known to have an integral role in establishing stable memories after learning events. The neuroplasticity induced by Pavlovian fear conditioning has likewise been shown to rely on interactions between BDNF and its principal receptor, tyrosine kinase receptor B (TrkB), in the amygdala after training. Although the necessity of amygdala bdnf expression and TrkB activation for associative learning within aversive contexts has been explored, it is unclear to what extent this interaction is involved in appetitive learning. It is also unclear whether the noted increases in amygdala BDNF after fear conditioning are due to local gene transcription and translation or anterograde transmission from cortical regions. To address both of these questions, we used two lentiviral approaches in mice, using both fear conditioning and cocaine-conditioned place preference (CPP), during acquisition and extinction. First, we decreased expression of bdnf mRNA in the amygdala of homozygous floxed mice with a Cre-expressing virus. In a second set of studies, we infused a virus that expressed a dominant-negative TrkB isoform into the same region. These approaches significantly impaired consolidation of fear conditioning and cocaine-CPP, as well as extinction of CPP. Together, these data suggest that BDNF-TrkB signaling is critical for amygdala-dependent learning of both appetitive and aversive emotional memories.
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Affiliation(s)
- Scott A. Heldt
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - Kelsey Zimmermann
- Department of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, and
| | - Kathryn Parker
- Department of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, and
| | - Meriem Gaval
- Department of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, and
| | - Kerry J. Ressler
- Department of Psychiatry and Behavioral Sciences, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, and
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
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23
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Acetazolamide attenuates chemical-stimulated but not thermal-stimulated acute pain in mice. Acta Pharmacol Sin 2014; 35:41-7. [PMID: 24335844 DOI: 10.1038/aps.2013.149] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 09/18/2013] [Indexed: 11/08/2022] Open
Abstract
AIM Acetazolamide (AZA), a carbonic anhydrase (CA) inhibitor, has been found to alleviate inflammatory and neuropathic pain in rats. In the present study, we investigated the effects of AZA on thermal- and chemical-stimulated acute pain in mice and the possible mechanisms underlying the effects. METHODS Five acute pain models based on thermal and chemical stimuli were established to investigate the effects of AZA on different types of nociception in mice. The antinociceptive effects of methazolamide (another CA inhibitor) and diazepam (a positive allosteric modulator of GABAA receptor) were also examined. The drugs were administered either intraperitoneally (ip) or intrathecally. RESULTS AZA (50-200 mg/kg, ip) did not produce analgesia in two thermal-stimulated acute pain models, ie, mouse tail-flick and hot-plate tests. In contrast, AZA (50-200 mg/kg, ip) dose-dependently reduced paw licking time in both capsaicin and formalin tests in mice. A similar result was observed in a mouse acetic acid-induced writhing test. However, AZA (10 nmol/mouse, intrathecally) did not produce significant analgesia in the 3 chemical-stimulated acute pain models. In addition, methazolamide (50-200 mg/kg, ip) and diazepam (0.25-1.0 mg/kg, ip) did not produce significant analgesia in either thermal- or chemical-stimulated acute pain. CONCLUSION AZA produces analgesia in chemical-stimulated, but not thermal-stimulated acute pain in mice. The attenuation of chemical-stimulated acute pain by AZA may not be due to enhancement of GABAA receptor-mediated inhibition via inhibiting CA activity but rather a peripheral ion channel-related mechanism.
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Tabakoff B, Hoffman PL. The neurobiology of alcohol consumption and alcoholism: an integrative history. Pharmacol Biochem Behav 2013; 113:20-37. [PMID: 24141171 PMCID: PMC3867277 DOI: 10.1016/j.pbb.2013.10.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 01/17/2023]
Abstract
Studies of the neurobiological predisposition to consume alcohol (ethanol) and to transition to uncontrolled drinking behavior (alcoholism), as well as studies of the effects of alcohol on brain function, started a logarithmic growth phase after the repeal of the 18th Amendment to the United States Constitution. Although the early studies were primitive by current technological standards, they clearly demonstrated the effects of alcohol on brain structure and function, and by the end of the 20th century left little doubt that alcoholism is a "disease" of the brain. This review traces the history of developments in the understanding of ethanol's effects on the most prominent inhibitory and excitatory systems of brain (GABA and glutamate neurotransmission). This neurobiological information is integrated with knowledge of ethanol's actions on other neurotransmitter systems to produce an anatomical and functional map of ethanol's properties. Our intent is limited in scope, but is meant to provide context and integration of the actions of ethanol on the major neurobiologic systems which produce reinforcement for alcohol consumption and changes in brain chemistry that lead to addiction. The developmental history of neurobehavioral theories of the transition from alcohol drinking to alcohol addiction is presented and juxtaposed to the neurobiological findings. Depending on one's point of view, we may, at this point in history, know more, or less, than we think we know about the neurobiology of alcoholism.
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Affiliation(s)
- Boris Tabakoff
- University of Colorado School of Medicine, MS8303, 12800 E. 19 Ave., Aurora, CO 80045 U.S.A
| | - Paula L. Hoffman
- University of Colorado School of Medicine, MS8303, 12800 E. 19 Ave., Aurora, CO 80045 U.S.A
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25
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Mou L, Dias BG, Gosnell H, Ressler KJ. Gephyrin plays a key role in BDNF-dependent regulation of amygdala surface GABAARs. Neuroscience 2013; 255:33-44. [PMID: 24096136 DOI: 10.1016/j.neuroscience.2013.09.051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 09/18/2013] [Accepted: 09/23/2013] [Indexed: 11/19/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is critically involved in synaptic plasticity and neurotransmission. Our lab has previously found that BDNF activation of neurotrophic tyrosine kinase, receptor, type 2 (TrkB) is required for fear memory formation and that GABAA receptor (GABAAR) subunits and the GABAA clustering protein gephyrin are dynamically regulated during fear memory consolidation. We hypothesize that TrkB-dependent internalization of GABAARs may partially underlie a transient period of amygdala hyperactivation during fear memory consolidation. We have previously reported that BDNF modulates GABAAR α1 subunit sequestration in cultured hippocampal and amygdala neurons by differential phosphorylation pathways. At present, no studies have investigated the regulation of gephyrin and GABAAR α1 subunits following BDNF activation in the amygdala. In this study, we confirm the association of GABAAR α1 and γ2 subunits with gephyrin on mouse amygdala neurons by coimmunoprecipitation and immunocytochemistry. We then demonstrate that rapid BDNF treatment, as well as suppression of gephyrin protein levels on amygdala neurons, induced sequestration of surface α1 subunits. Further, we find that rapid exposure of BDNF to primary amygdala cultures produced decreases in gephyrin levels, whereas longer exposure resulted in an eventual increase. While total α1 subunit levels remained unchanged, gephyrin was downregulated in whole cell homogenates, but enhanced in complexes with GABAARs. Our data with anisomycin suggest that BDNF may rapidly induce gephyrin protein degradation, with subsequent gephyrin synthesis occurring. Together, these findings suggest that gephyrin may be a key factor in BDNF-dependent GABAAR regulation in the amygdala. This work may inform future studies aimed at elucidating the pathways connecting BDNF, GABAA systems, gephyrin, and their role in underlying amygdala-dependent learning.
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Affiliation(s)
- L Mou
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
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26
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Avolio E, Facciolo RM, Alò R, Mele M, Carelli A, Canonaco A, Mosciaro L, Talani G, Biggio G, Sanna E, Mahata SK, Canonaco M. Expression variations of chromogranin A and α1,2,4 GABA(A)Rs in discrete limbic and brainstem areas rescue cardiovascular alterations. Neurosci Res 2013; 77:8-15. [PMID: 23916832 DOI: 10.1016/j.neures.2013.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/08/2013] [Accepted: 07/24/2013] [Indexed: 12/21/2022]
Abstract
Recent interferences of hemodynamic functions via modified brain neuronal mechanisms have proven to be major causes of dementia and sleeping disorders. In this work, cerebral expression differences of the neuroactive vesicular chromogranin A (CgA) and distinct α GABA(A)R subunits were detected in the facultative hibernating hamster. In particular, damaged neuronal fields of hypotensive torpor (TORP) state were correlated to elevated CgA and GABA(A)R α1, α4 mRNA levels in the paraventricular hypothalamic nucleus (PVN), central amygdalar nucleus (CeA) plus solitary tractus nucleus (NTS). Conversely, few neurodegeneration signals of hypertensive arousal (AROU) state, accounted for mostly lower CgA levels in the same areas. This state also provided increased α2-containing sites in amygdala, hippocampal and NTS neurons together with elevated α4-containing receptors in the periventricular hypothalamic nucleus (Pe). Interestingly in our hibernating model, CgA appeared to preferentially feature inhibitory neurosignals as indicated by preliminary perfusion of amygdalar sites with its highly specific antihypertensive derived peptide (catestatin) promoting GABA-dependent sIPSCs. Overall, evident neuronal damages plus altered expression capacities of CgA and α1-, α2-, α4-GABA(A)Rs in CeA, Pe, PVN as well as NTS during both hibernating states corroborate for the first time key molecular switching events guaranteeing useful cardiovascular rescuing abilities of neurodegenerative disorders.
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Affiliation(s)
- Ennio Avolio
- Comparative Neuroanatomy Laboratory, University of Calabria, Ponte P. Bucci 4B, 87030 Arcavacata di Rende, Cosenza, Italy; Health Center srl, via Alimena 6, 87100 Cosenza, Italy; VA San Diego Healthcare System/Department of Medicine, University of California-San Diego, La Jolla, CA 92093-0838, USA
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Rihel J, Schier AF. Sites of action of sleep and wake drugs: insights from model organisms. Curr Opin Neurobiol 2013; 23:831-40. [PMID: 23706898 DOI: 10.1016/j.conb.2013.04.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 04/11/2013] [Accepted: 04/15/2013] [Indexed: 01/21/2023]
Abstract
Small molecules have been used since antiquity to regulate our sleep. Despite the explosion of diverse drugs to treat problems of too much or too little sleep, the detailed mechanisms of action and especially the neuronal targets by which these compounds alter human behavioural states are not well understood. Research efforts in model systems such as mouse, zebrafish and fruit fly are combining conditional genetics and optogenetics with pharmacology to map the effects of sleep-promoting drugs onto neural circuits. Recent studies raise the possibility that many small molecules alter sleep and wake via specific sets of critical neurons rather than through the global modulation of multiple brain targets. These findings also uncover novel brain areas as sleep/wake regulators and indicate that the development of circuit-selective drugs might alleviate sleep disorders with fewer side effects.
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Affiliation(s)
- Jason Rihel
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
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28
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Song C, Xu XB, He Y, Liu ZP, Wang M, Zhang X, Li BM, Pan BX. Stuttering interneurons generate fast and robust inhibition onto projection neurons with low capacity of short term modulation in mouse lateral amygdala. PLoS One 2013; 8:e60154. [PMID: 23527307 PMCID: PMC3602081 DOI: 10.1371/journal.pone.0060154] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Accepted: 02/21/2013] [Indexed: 11/18/2022] Open
Abstract
The stuttering interneurons (STi) represent one minor subset of interneuron population and exhibit characteristic stuttering firing upon depolarization current injection. While it has been long held that the GABAergic inhibitory transmission largely varies with the subtype identity of presynaptic interneurons, whether such a rule also applies to STi is largely unknown. Here, by paired recording of interneuron and their neighboring projection neuron in lateral amygdala, we found that relative to the fast spiking and late spiking interneurons, the STi-evoked unitary postsynaptic currents onto the projection neurons had markedly larger amplitude, shorter onset latency and faster rising and decay kinetics. The quantal content and the number of vesicles in the readily releasable pool were also larger in synapses made by STi versus other interneurons. Moreover, the short-term plasticity, as reflected by the paired pulse depression and depolarization-induced suppression of inhibition, was the least prominent in the output synapses of STi. Thus, the fast and robust inhibition together with its low capacity of short term modulation may suggest an important role for STi in preventing the overexcitation of the projection neurons and thus gating the information traffic in amygdala.
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Affiliation(s)
- Chen Song
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
| | - Xiao-Bin Xu
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
| | - Ye He
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
- Department of Pharmacology, Nanchang University, Nanchang, China
| | - Zhi-Peng Liu
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
| | - Min Wang
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
| | - Xin Zhang
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
| | - Bao-Ming Li
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
| | - Bing-Xing Pan
- Laboratory of Fear and Anxiety Disorder, Institute of Life Science, Nanchang University, Nanchang, China
- * E-mail:
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29
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Heldt SA, Mou L, Ressler KJ. In vivo knockdown of GAD67 in the amygdala disrupts fear extinction and the anxiolytic-like effect of diazepam in mice. Transl Psychiatry 2012; 2:e181. [PMID: 23149445 PMCID: PMC3565763 DOI: 10.1038/tp.2012.101] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In mammals, γ-aminobutyric acid (GABA) transmission in the amygdala is particularly important for controlling levels of fear and anxiety. Most GABA synthesis in the brain is catalyzed in inhibitory neurons from L-glutamic acid by the enzyme glutamic acid decarboxylase 67 (GAD67). In the current study, we sought to examine the acquisition and extinction of conditioned fear in mice with knocked down expression of the GABA synthesizing enzyme GAD67 in the amygdala using a lentiviral-based (LV) RNA interference strategy to locally induce loss-of-function. In vitro experiments revealed that our LV-siRNA-GAD67 construct diminished the expression of GAD67 as determined with western blot and fluorescent immunocytochemical analyses. In vivo experiments, in which male C57BL/6J mice received bilateral amygdala microinjections, revealed that LV-siRNA-GAD67 injections produce significant inhibition of endogenous GAD67 when compared with control injections. In contrast, no significant changes in GAD65 expression were detected in the amygdala, validating the specificity of LV knockdown. Behavioral experiments showed that LV knockdown of GAD67 results in a deficit in the extinction, but not the acquisition or retention, of fear as measured by conditioned freezing. GAD67 knockdown did not affect baseline locomotion or basal measures of anxiety as measured in open field apparatus. However, diminished GAD67 in the amygdala blunted the anxiolytic-like effect of diazepam (1.5 mg kg(-1)) as measured in the elevated plus maze. Together, these studies suggest that of GABAergic transmission in amygdala mediates the inhibition of conditioned fear and the anxiolytic-like effect of diazepam in adult mice.
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Affiliation(s)
- S A Heldt
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.
| | - L Mou
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA
| | - K J Ressler
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, GA, USA,Howard Hughes Medical Institute, Bethesda, MD, USA
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30
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Reduction of Pain Behavior by Stimulation of the Basolateral Amygdalar Nuclei in Freely Moving Rats. NEUROPHYSIOLOGY+ 2012. [DOI: 10.1007/s11062-012-9310-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Cell-type specific deletion of GABA(A)α1 in corticotropin-releasing factor-containing neurons enhances anxiety and disrupts fear extinction. Proc Natl Acad Sci U S A 2012; 109:16330-5. [PMID: 22992651 DOI: 10.1073/pnas.1119261109] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Corticotropin-releasing factor (CRF) is critical for the endocrine, autonomic, and behavioral responses to stressors, and it has been shown to modulate fear and anxiety. The CRF receptor is widely expressed across a variety of cell types, impeding progress toward understanding the contribution of specific CRF-containing neurons to fear dysregulation. We used a unique CRF-Cre driver transgenic mouse line to remove floxed GABA(A)α1 subunits specifically from CRF neurons [CRF-GABA(A)α1 KO]. This process resulted in mice with decreased GABA(A)α1 expression only in CRF neurons and increased CRF mRNA within the amygdala, bed nucleus of the stria terminalis (BNST) and paraventricular nucleus of the hypothalamus. These mice show normal locomotor and pain responses and no difference in depressive-like behavior or Pavlovian fear conditioning. However, CRF-GABA(A)α1 KO increased anxiety-like behavior and impaired extinction of conditioned fear, coincident with an increase in plasma corticosterone concentration. These behavioral impairments were rescued with systemic or BNST infusion of the CRF antagonist R121919. Infusion of Zolpidem, a GABA(A)α1-preferring benzodiazepine-site agonist, into the BNST of the CRF-GABA(A)α1 KO was ineffective at decreasing anxiety. Electrophysiological findings suggest a disruption in inhibitory current may play a role in these changes. These data indicate that disturbance of CRF containing GABA(A)α1 neurons causes increased anxiety and impaired fear extinction, both of which are symptoms diagnostic for anxiety disorders, such as posttraumatic stress disorder.
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Saari TI, Uusi-Oukari M, Ahonen J, Olkkola KT. Enhancement of GABAergic activity: neuropharmacological effects of benzodiazepines and therapeutic use in anesthesiology. Pharmacol Rev 2011; 63:243-67. [PMID: 21245208 DOI: 10.1124/pr.110.002717] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
GABA is the major inhibitory neurotransmitter in the central nervous system (CNS). The type A GABA receptor (GABA(A)R) system is the primary pharmacological target for many drugs used in clinical anesthesia. The α1, β2, and γ2 subunit-containing GABA(A)Rs located in the various parts of CNS are thought to be involved in versatile effects caused by inhaled anesthetics and classic benzodiazepines (BZD), both of which are widely used in clinical anesthesiology. During the past decade, the emergence of tonic inhibitory conductance in extrasynaptic GABA(A)Rs has coincided with evidence showing that these receptors are highly sensitive to the sedatives and hypnotics used in anesthesia. Anesthetic enhancement of tonic GABAergic inhibition seems to be preferentially increased in regions shown to be important in controlling memory, awareness, and sleep. This review focuses on the physiology of the GABA(A)Rs and the pharmacological properties of clinically used BZDs. Although classic BZDs are widely used in anesthesiological practice, there is a constant need for new drugs with more favorable pharmacokinetic and pharmacodynamic effects and fewer side effects. New hypnotics are currently developed, and promising results for one of these, the GABA(A)R agonist remimazolam, have recently been published.
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Affiliation(s)
- Teijo I Saari
- Department of Anesthesiology, Intensive Care, Emergency Care and Pain Medicine, Turku University Hospital, P.O. Box 52 (Kiinamyllynkatu 4-8), FI-20520 Turku, Finland.
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